Among methods under active study for curative cancer therapy is the use of labeled monoclonal antibodies directed against tumor- specific or tumor-associated antigens. The efficacy of such strategies can be accurately modeled using computer programs involving compartmental analysis. Two major components of this treatment can be developed with our models: 1. The dosimetry resulting from the circulation and localization of the labeled antibodies. This dosimetry investigation is essential to the development and approval of clinical protocols. 2. The optimization of the localization of the activity through time- dependent infusion of the antibodies. Future studies to be undertaken during the period of the grant include modeling for magnetic resonant imaging (NMR) studies of the evolution of cerebral circulation during the course of radiation therapy.